Host preference and survivorship of Euschistus heros strains on cotton and soybean

Abstract The Neotropical brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), is a key pest of soybean, Glycine max (L.) Merrill (Fabaceae), and recently became an economically important pest of cotton, Gossypium hirsutum L. (Malvaceae), in Brazil. This stink bug has two allopatric strains, one prevalent in southern Brazil (SS), and another in the north (NS). The two strains hybridize in central Brazil. Knowledge of host preferences and host suitability of these strains may clarify the contribution of the various gene pools to contemporary adaptive features such as the ability to harm cotton crops. We tested the attraction of the E. heros strains and reciprocal hybrids – ♀N × ♂S (HNS) and ♀S × ♂N (HSN) – to soybean and cotton leaves and reproductive structures, and evaluated the nymph development and survivorship of the two strains and reciprocal hybrids fed on soybean or cotton. We conducted host‐choice experiments with fourth instars and adult females and evaluated the survival of immatures on soybean and cotton plants under laboratory conditions. The SS strain preferred soybean over cotton. Hybrid and NS strains chose randomly between soybean and cotton plants. All strains developed on soybean, with similar survival rates. On cotton, pure strains did not reach adulthood; however, hybrids developed on cotton but with a survival rate of <1%. Our results showed that the SS strain of E. heros was more attracted to soybeans, and NS and hybrid strains had a polyphagous choice behavior, suggesting that current host selection has been mediated by historical and, mainly, contemporary relationships of E. heros strains with these hosts.